1&period;Wire into the plant must be stored in dry conditions&comma; can not open wire reel waterproof package&period;2&period;Welding shall be removed before welding surface oil&comma; rust&comma;water and other impurities&period;3&period;The CO2 gas protection&comma; CO2gas purity 99&period;98&percnt;&period;4&period;CO2 welding protective gas flow rate should be controlled at 20~25L&sol;min&period;5&period;Wire extension length should be controlled in the range of 15~25mm&period;6&period;Preheatig before welding to weld 150ºC~300ºC&comma; 700ºC~740ºC tempering treatment only after&period;